Method of applying surgical clips to tissue

ABSTRACT

A flexible clip applier includes a flat wire wound outer tubular coil, a pair of jaws at the end of the coil, end effector wires extending through the coil and coupled to the jaws, and a clip-advancing wire extending through the coil. A large pushing force to advance a clip is created by providing a compressive force to the outer tubular coil to increase its tensile limitation, and providing a force which is compressive to the clip-advancing wire and tensile to the tubular coil while maintaining the compressive force on the tubular coil.

This application is a continuation-in-part of U.S. Ser. No. 09/891,775,filed Jun. 25, 2001, now U.S. Pat No. 6,716,226, which is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to methods of using surgical devices. Inparticular, this invention relates to a method of using a surgical clipapplier to apply a surgical clip over tissue and to deform the clip toenhance retention.

2. State of the Art

Surgical clips are generally used to apply clamping force to ducts,vessels, and other tissues. In addition, surgical clips are particularlyuseful in controlling bleeding of a tissue in lieu of suturing orstapling where suturing or stapling is difficult.

All of the currently available surgical multifiring clip appliers aresubstantially rigid devices intended to extend through a trocar port orthrough an incision to a surgical site requiring application of a clip.The devices have been rigid because a stiff pushing element has beenrequired in order to exert the required pushing force to move the clipover the tissue.

However, there is a substantial need for a flexible clip applier,particularly one insertable through a lumen of an endoscope. The abilityto apply clips through an endoscope would permit myriad minimallyinvasive surgical solutions to medical problems, especially those of thegastrointestinal tract. However, it is accepted theory that thetransmitted force required to advance or form a clip over tissue cannotbe produced in the distalmost end of a long flexible device that iscommonly constructed with a metal tubular coil, or polymer tube, such asan endoscopic device or catheter. For example, C. Paul Swain, MD, arecognized expert in endoscopic instruments and particularly endoscopicstapling devices, has stated that “[i]t is hard to exert more than 200 gof force on the tissue when pushing . . . . This fact is of course onefeature that makes intervention at flexible endoscopy relatively safe”.See C. Paul Swain, “What Endoscopic Accessories Do We Really Need?”,Emerging Technologies in Gastrointestinal Endoscopy, Gastrointest.Endosc., Vol. 7, No. 2, pp. 313-330 (April 1997). Yet, a pushing forcesubstantially greater than 200 g is required to push a clip overcompressed tissue. In fact, it is believed a force in excess of 500grams (1.1 lbs) is required for a satisfactory instrument, andsubstantially greater forces, e.g., in excess of 1500 grams (3.3 lbs)would be desirable.

Generally a flexible endoscopic device (e.g., a biopsy forceps device)includes an outer tubular member, typically being constructed of a metaltubular coil or a polymer tube which is poor in transmitting forces thatimpart tensile stresses to the outer sheath, a control elementlongitudinally movable relative to the tubular member, an end effectorcoupled to the distal ends of both the tubular member and the controlelement such that relative movement of the control element and thetubular member causes operation of the end effector, and a handle whichmoves the control element relative to the handle. This type of flexibleendoscopic instrument is limited in the amount of pushing force it cangenerate for several reasons. Compression of a flexible control element(pushing element) tends to cause the pushing element to buckle withinthe outer flexible sheath of the device. If a relatively larger diameterflexible pushing element is used such that it better resists buckling,the pushing element may impart too much stiffness to the flexing of theendoscopic instrument. In addition, a flexible pushing element of largerdiameter is subject to greater frictional forces within the outer sheathwhich reduces the force transmitted from the handle to the end effector.If the flexible pushing element is made relatively smaller in diameter,it is subject to kinking which will result in little to no forcetransmitted to the distal end. Kinking is especially a problem inendoscopic instruments, as the endoscope and its lumen may be extendedthrough a tortuous path. For these reasons and others, mechanicalapplication of a relatively large distal end pushing force andparticularly clip application have been absent from the capability offlexible endoscopic tools.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a flexibleendoscopic device capable of generating a relatively large pushing forceat its distal end.

It is another object of the invention to provide an endoscopic clipapplier.

It is a further object of the invention to provide a flexible clipapplier which can exert a pushing force of at least 500 grams (1.1 lbs),and preferably in excess of 1500 grams (3.3 lbs) via a manuallyactuatable handle.

It is an additional object of the invention to provide a surgical clipapplier which is adapted for use in minimally invasive surgery.

It is also an object of the invention to provide a surgical clip applierwhich has a pushing element which is not subject to kinking.

It is yet another object of the invention to provide a surgical clipapplier which has a pushing element which does not create unsuitablyhigh frictional forces within the outer sheath.

It is still a further object of the invention to provide a surgical clipapplier which can store and apply multiple clips.

In accord with these objects, which will be discussed in detail below, asurgical clip applier is provided having a flexible, preferably flatwire wound outer tubular coil, a pair of jaws at the distal end of thetubular coil, a set of end effector wires extending through the outertubular coil and coupled to the jaws, and a clip-advancing wireextending through the tubular coil. A lubricious, preferably extrudedpolymer, multilumen barrier sheath extends within the tubular coil andseparates the wires from each other and the tubular coil. A clip chamberis provided in the distal end of the tubular coil and stores a pluralityof linearly arranged clips. A clip pusher is provided at a distal end ofthe clip-advancing wire, and adapted to advance the clips in the chambertoward the jaws when the clip-advancing wire is advanced through thebarrier sheath and outer tubular coil. The jaws include clampingsurfaces which operate to compress tissue between the jaws when the jawsare closed, guides in which a distalmost clip rides distally and isadvanced over the clamped tissue when the line of clips is advanced bythe clip pusher, and a distal anvil which operates to bend a portion ofthe distalmost clip to enhance its retention on the clamped tissue. Aproximal handle is provided for movement of the clip-advancing wire andend effector wires relative to the barrier sheath to effect (1) clampingand rotation of the jaws (relative to each other and about thelongitudinal axis of the tubular coil), and (2) advancement of theclip-advancing wire to effect distal movement of a clip.

The flat wire wound tubular coil is preferred over round wire (thoughnot necessarily required over a round wire wound tubular coil) becauseit is flexible, yet sufficiently longitudinally stiff such that thedevice may be pushed through the lumen of the endoscope. In addition,the flat wire wound tubular coil can be made with a high preload and hasa tensile spring constant sufficiently high that it resists buckling anduncoiling during application of a pushing force by the handle againstthe clip-advancing wire. The clip-advancing wire has a sufficientlylarge diameter to transmit force, yet small enough to minimize internalfriction when moved within a device flexed through a tortuous path in anendoscope. The end effector wires are large enough to handle the highclosing force from the handle, and to resist compressive buckling whenmoved in an opposite direction, yet small enough to be coupled todiminutive jaws. The multilumen barrier sheath supports theclip-advancing wire and end effector wires along their length to reducecompressive buckling, and provides a separation layer to reducefriction. Movement of the clip-advancing wire relative to the outertubular coil causes a compressive force in the clip-advancing wire andtensile forces in the outer tubular member such that a relative pushingforce is transmitted to the distal end of the clip-advancing wire inexcess of the perceived threshold of the 200 grams (0.44 lbs). In fact,one embodiment of the device of the invention, sized for endoscopic use,provides a pushing force in excess of 2267 grams (5 lbs).

In operation, the jaws can be moved through a working channel of anendoscope in a closed position. Once exited, the handle can be operatedto open the jaws and rotate the jaws to a desired orientation. The jawsare positioned on either side of tissue about which it is desired toplace a clip and the handle is operated to pull the end effector wiressuch that the jaws clamp about the tissue. The handle is then locked tomaintain the jaws in the clamped position. The handle is operated toeffect advancement of the clip-advancing wire through the tubular coilsuch that a clip is advanced through the jaw guides and over the tissue.The clip is advanced until a portion thereof is forced against the anvilof the jaws to effect bending of the clip portion such that that portionmoves laterally to pierce the clamped tissue. After the clip is applied,the jaws are released from about the tissue, and the end effectorassembly may then be moved to another tissue location to applyadditional clips.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial section side elevation view of a surgical clipapplier according to the invention, shown with the handle configured toprovide the jaws in an open configuration;

FIG. 2 is a broken perspective view of a distal portion of the clipapplier according to the invention;

FIG. 2A is an exploded and broken perspective view of a distal portionof the clip applier according to the invention;

FIG. 2B is a broken schematic view of a distal end of the clip-advancingwire and the coil connector;

FIG. 2C is a broken schematic view of a distal end of the clip-advancingwire and the coil connector illustrating the limitation on proximalmovement of the clip-advancing wire relative to the coil connector;

FIG. 3 is a perspective view of the jaw assembly of the clip applieraccording to the invention, and a clip;

FIG. 4 is a partial section side elevation view of a surgical clipapplier according to the invention, showing the right side of the handlepositioned to place the jaws in an unloaded closed configuration;

FIG. 4A is a view similar to FIG. 4, illustrating alternativeembodiments to the handle of the clip applier according to theinvention;

FIG. 5 is an enlarged view of the handle of the surgical clip applierwith the handle in the same position as shown in FIG. 4;

FIG. 6 is a view similar to FIG. 4 of the left side of the handle;

FIG. 7 is a view similar to FIG. 6 with the addition of the varioussprings;

FIG. 8 is an enlarged broken section view of the proximal left side ofthe handle of the clip applier according to the invention;

FIG. 9 is an enlarged side perspective view of the end effectorassembly;

FIG. 10 is an enlarged distal end perspective view of the end effectorassembly;

FIG. 11 is a broken partial section side elevation view of the distalend of the clip applier according to the invention;

FIG. 12 is a view similar to FIG. 1, showing the handle configured suchthat the jaws are in a unloaded closed position, and shown without thepinion on the jaw closing lever;

FIG. 13 is a partial section perspective view of a surgical clip applieraccording to the invention, illustrating rotation of the end effectorassembly by operation of the rotation knob;

FIG. 14 is a partial section side elevation view of a surgical clipapplier according to the invention, showing the jaws in a clampedconfiguration;

FIG. 15 is a partial section side elevation view of a surgical clipapplier according to the invention, showing the jaws in a clampedconfiguration and the clip-advancing lever actuated;

FIG. 16 is an enlarged partial section view of the handle of thesurgical clip applier, showing the clip-advancing lever actuated;

FIG. 17 is a longitudinal section view of the distal end of the clipapplier according to the invention, shown with the jaws in a closedconfiguration and a formed clip therebetween;

FIG. 18 is a broken partial section side elevation view of the distalend of the clip applier according to the invention, shown with the jawsin an open configuration and a formed clip therebetween;

FIG. 19 is a broken partial section side elevation view of the distalend of the clip applier according to the invention, shown with the jawsin an open configuration, the formed clip released, and the retainer ofa subsequent clip protruding between the jaws;

FIG. 20 is a longitudinal section view of the distal end of the clipapplier according to the invention, shown with the jaws in an openconfiguration and the retainer retracted relative to the view of FIG.19;

FIG. 21 is a partial section side elevation view of a surgical clipapplier according to the invention, shown with the jaws in an openposition and a formed clip released therefrom;

FIG. 22 is a table listing dimensions for the tubular coil,clip-advancing wire, and end effector wires of six prototypes, and theresultant output force achieved with the prototype; and

FIG. 23 is an efficiency plot of the prototypes described in the tableof FIG. 22.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIGS. 1, 2, 2A and 3, a flexible clip applier 10 suitablefor insertion through a working channel (lumen) of an endoscope isshown. The clip applier 10 generally includes a flexible, flat wirewound outer tubular coil 12 having an end effector assembly 13 mountedat a distal end 16 thereof. The end effector assembly 13 includes aclevis (jaw mount) 14 rotatably supporting a pair of jaws 18, 20. Endeffector wires 22, 24 extend through the tubular coil 12 and have distalends 26 respectively coupled to the jaws 18, 20. A clip-advancing wire30 extends through the tubular coil 12 and includes a distal end 32provided with a clip pusher 34. A lubricious, preferably extruded,multilumen barrier sheath 36 extends through substantially the entirelength of the outer tubular coil 12 and separates the end effector wires22, 24 and clip-advancing wire 30 from each other and the outer tubularcoil 12. A proximal handle assembly 40 is provided for moving the endeffector wires 22, 24 and clip-advancing wire 30 relative to the tubularcoil 12 to effect clamping and rotation of the jaws and advancement of aclip, as described in detail below.

Referring to FIGS. 4 and 5, more particularly, the handle assembly 40includes a housing defined by two shell portions 42, 44, a stationaryhandle 46, a jaw closing lever 48 linearly movable within a slot 50 inthe housing and relative to the stationary handle 46, and aclip-advancing lever 52 rotatably mounted on the jaw closing lever 48with a pivot pin 54. The jaw closing lever 48 is coupled to the endeffector wires 22, 24, as described in detail below. The jaw closinglever 48 is biased into an open position (away from the stationaryhandle 46) with a constant force spring 56 held in a distal portion ofthe housing such that the jaws 18, 20 are in an open configuration whenno manual force is applied against the force of the spring 56 to movethe jaw closing lever toward the stationary handle. The clip-advancinglever 52 is forced into an open position, also away from the stationaryhandle 46, with a torsion spring 58 (FIGS. 4 and 7). The clip-advancinglever 52 is coupled to the clip-advancing wire 30, as discussed indetail below, with rotation of the clip-advancing lever 52 operating tomove the clip pusher 34 at the distal end 32 of the clip-advancing wire30 longitudinally within the tubular coil.

A tube 60 extends from the interior of the handle 40 to the exterior andincludes a proximal rotation knob 62. The proximal end of theclip-advancing wire 30 is clamped, or otherwise held, within the tube 60such that rotation of the knob 62 causes rotation of the entireclip-advancing wire. A distal end 64 of the tube 60 is rotatably coupledwithin a collar 66. The collar 66 is fixedly coupled to a rack 68.Linear movement of the rack 68 within the housing causes the tube tomove longitudinally within and outside the housing.

Alternatively, referring to FIG. 4A, the tube 60 may be telescoping,having two rotationally interfering sections 60 a and 60 b, such thatmovement of the rack 68 moves a distal section 60 a of the tube relativeto a proximal section 60 b, thereby maintaining a constant length forextension of the proximal section 60 b of the tube outside the housing.The rotationally interfering portions, e.g., each having a hex shape,permit rotationally forces to be transmitted from the knob 62 to thedistal end 64 of the tube.

Referring back to FIG. 4, a pinion 70 is rotatably mounted at 72 to anupper portion 74 of the clip-advancing lever 52 and positioned to act onthe rack 68 when the clip-advancing lever is rotated. As such, when theclip-advancing lever 52 is rotated about pivot 54 toward the jaw closinglever 48, the rack 68 and the clip-advancing wire 30 are advanced. Therack 68 is preferably substantially longer than what is required by thenumber of teeth on the pinion 70. As a result, the pinion 70 can actupon the rack 68 in any location at which the jaw closing lever 48 maybe positioned upon closing the jaws 18, 20. This, when the jaw closinglever 48 is pulled back toward the stationary handle 46 to effectclosure of the jaws 18, 20 about tissue, the jaw closing lever 48 may belocated at a location which is consistent with the thickness andconsistency of the tissue about which the jaws are to be closed.

The teeth of the pinion 70 are preferably at a positive engagement anglerelative to the teeth of the rack 68 because of the location of thepinion pivot axis 72. Then, when the pinion is rotated, the rack ismoved longitudinally. A leaf spring 76 acts between the pinion 70, athole 78, and the advancing lever 52 at shelf 77 to force the pinion 70into the rack 68. After firing a clip, as discussed below, release ofthe clip-advancing lever 52 allows the spring 58 to return the lever 52back to its unbiased position, and the pinion 70 rotates about thepinion axis 72 against the leaf spring 76 and over the rack 68.

Turning now to FIGS. 6 through 8, the jaw closing lever 48 includes aspring activated catch system 80 which locks the jaw closing lever whena predetermined load is applied thereto rather than when the closinglever is located at any particular location. The catch system 80includes the following structures on an upper mount portion 82 of thejaw closing lever 48: a proximal spring mount 84; two spaced apart bolts86, 88; and a locking tooth 90. The locking tooth 90 includes a proximalcam 92. The catch system 80 further includes the following additionalstructures: a latch 94 having a linear slot 96 and a cam slot 98, whichare positioned over bolts 86, 88 respectively; an end effector wiremount 100 to which the proximal ends of the end effector wires 22, 24are attached; an upper cam surface 102 for the below-described leverlock 110; and a spring catch 104. An extension spring 106 (FIG. 7) isheld between the spring mount 84 and spring catch 104. A generallyL-shaped lever lock 110 is rotatably coupled about a lever pivot 114formed at the proximal end of the handle. An elongate portion 116 of thelock 110 includes a comb; i.e., the portion 116 includes a plurality ofteeth 118, each of which include a distal camming surface 120. Anotherportion 122 of the lever lock 110 is provided with a release button 124which extends outside of the handle housing. A torsion spring 130 isprovided about the pivot 114 to bias the lever lock 110 down toward thelocking tooth 90. A safety 132 is also provided to prevent release ofthe jaw closing lever 48 when the clip-advancing lever 52 is moved froman unbiased position, thereby preventing inadvertent release ofunapplied clips.

Once the jaws are closed about tissue, as discussed further below, it isdesired to maintain their closed position until a clip is advanced overthe tissue. In view of this object, the catch system 80 function asfollows. Still referring to FIGS. 6 through 8, the cam surface 102 isgenerally adapted to position the teeth 118 of the lever lock 110located in front of the locking tooth 90 above the locking tooth, suchthat the jaw closing lever 48 may be moved linearly. When the jawclosing lever 48 is moved toward the stationary lever 46, tension isincreased in the end effector wires 22, 24 to move the jaws 18, 20 froman open position to a closed position. As the tension increases in theend effector wires 22, 24 and exceeds the tension of the extensionspring 106, the latch 94 moves distally relative to the jaw closinglever 48. Then, movement of the jaw closing lever 48 relative to thelatch 94 causes the bolts 86, 88 to ride within the linear slot 96 andthe camming slot 98, respectively. Referring to FIG. 8, movement of bolt88 within camming slot 98 forces the proximal end of the latch 94downward and permits the lever lock 110 to rotate clockwise. This causesthe locking tooth 90 to engage the toothed portion 116 of the lever lock110 and lock the position of the jaw closing lever 48. The load appliedto the end effector wires is then limited to the force applied by theextension spring 106 (FIG. 7). The jaw closing lever 48 then may bereleased by pushing the release button 124 sufficiently to rotate thelever lock 110 against the bias of the torsion spring 130 and clear thelocking tooth 90.

Turning now to FIGS. 1, 2, 4 and 6, the distal end of the housing 42, 44of the handle assembly 40 includes a slot 131 in which two preferablysubstantially rigid and preferably low friction tubes 133, 135, e.g.,brass tubes, are provided. The proximal end 136 of the tubular coil 12is coupled to the housing in alignment with the tubes 133, 135 with aflare nut coupling 138 or an equivalent assembly. The clip-advancingwire 30 extends from the rotation tube 60 through tube 133 and into aclip-advancing wire lumen 140 of the barrier sheath 36. Theclip-advancing wire 30 extends therethrough to the distal end 16 of thetubular coil 12. The end effector wires 22, 24 extend from end effectorwire mount 100 through tube 135 and into respective end effector wirelumina 142, 144 of the barrier sheath 36, and then extend therethroughto the distal end of the tubular coil. Wires 22, 24 and 30 are providedin separate lumina within the barrier sheath 36 in order to minimizefriction between the wires and reduce buckling and kinking of the wiresalong the length of the tubular coil 12.

Turning again to FIG. 4A, rather than using tubes to direct the wiresfrom the housing into the barrier sheath in tubular coil, the housingmay be formed with channels which provide the same function. Forexample, channels 132 a, 132 b are adapted to direct the clip-advancingwire 30 and end effector wires 22, 24, respectively, into the barriersheath 36 within the tubular coil 12. In addition, the housing may beformed with distal structure, e.g., a cylindrical protrusion 146,facilitating the coupling of a flare nut assembly thereto.

Referring back to FIG. 2, the tubular coil 12 is a preferably stainlesssteel (or other metal or metal alloy) flat wire wound wire tubular coil,though a round wire wound tubular coil may be used. The tubular coil 12is fairly stiff such that the device can be pushed through the endoscopeto the treatment area. The tubular coil 12 has a spring constantsufficiently high in order to resist uncoiling when subject to thetensile load created when the handle applies a pushing force to theclip-advancing wire and the clips, as discussed in more detail below,and minimize buckling during force transmission. In addition, thetubular coil 12 is preloaded such that each turn is substantially incontact with the adjacent turns 360° around the tubular coil. The outerdiameter of the tubular coil 12 has an outer diameter smaller than theinner diameter of the working channel (lumen) of an endoscope for whichit is intended, and the inner diameter of the tubular coil should bemaximized so that it may readily accept the barrier sheath, andclip-advancing wire and end effector wires, as well as form a chamberfor a plurality of clips, as discussed below. In preferred embodiments,the tubular coil 12 of a device adapted for an endoscope having a 3.2 mmworking channel has an outer diameter preferably not exceedingapproximately 3.175 mm (0.125 inch), and a preferably an inner diameterof at least approximately 0.90 mm (0.035 inch) so that it may accept theend effector wires 22, 24, clip-advancing wire 30, barrier sheath 36,and clips 202. The tubular coil inner diameter preferably corresponds tothe transverse dimension of a clip 202, discussed below, so that theclip is stably directed through the chamber 200. The wire of the tubularcoil 12 has a width W preferably between approximately 0.635 mm to 1.270mm (0.025 inch to 0.050 inch), and a thickness T preferably at leastapproximately 0.13 mm to 0.75 mm (0.005 inch to 0.030 inch). The tubularcoil length should at least be the length of the endoscope workingchannel, generally 150 cm to 250 cm. A substantial length of the tubularcoil 12 is preferably covered in a high density polyethylene (HDPE)sheath 150 (FIGS. 1, 2 and 2A).

The barrier sheath 36 within the tubular coil is preferably non-circularin shape to reduce contact points and thereby minimize friction betweenthe barrier sheath and the tubular coil. The primary purpose of thesheath is to maintain a close fitting bearing surface for theclip-advancing wire, although its three distinct lumina help reducefriction between all the wires. The sheath 36 preferably free floatswithin the tubular coil; i.e., it is not attached to the tubular coil atits ends or along its length. Preferred cross-sectional shapes includegenerally rectangular and triangular (each with or without broken orrounded edges) and trefoil. The barrier sheath 36 is preferably anextrusion made from polypropylene, an FEP fluoropolymer resin (FEP),polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), nitrolpolyvinyl chloride, nylon, or any other lubricious polymer.

The clip-advancing wire 30 is preferably made of nickel-titanium alloy(NiTi) or stainless steel. The NiTi construction permits theclip-advancing wire 30 to transmit torque (by rotation of the rotationknob 62) without taking a cast, and with minimal whipping. Theclip-advancing wire 30 has a sufficiently large diameter to transmitforce, yet not so large that it is prevented from functioning through atortuous path or fit within the tubular coil 12. A preferred diameterfor the clip-advancing wire is approximately 0.375 mm to 0.89 mm (0.015inch to 0.035 inch).

Referring to FIGS. 2, 2A and 2B, the distal end 32 of the clip-advancingwire 30 has a non-circular cross-section, and is preferably rectangularin shape. The distal end 32 is preferably a length four to five timesthe length of the clip pusher 34. A coil connector 152 is coupled withinthe distal portion 16 of the tubular coil 12, e.g., by welding, pressfitting, interference fit, pinning, etc., preferably approximately 25 mmto 50 mm from the distal end of the tubular coil (i.e., the length of alinear arrangement of five or so clips), and includes a central keyhole156 having a non-circular cross section, and two end effector channels158 (only one shown) through which the end effector wires 22, 24 extend.The distal end 32 of the clip-advancing wire 30 can be longitudinallymoved through the keyhole 156, with the transition 159 of theclip-advancing wire 30 from non-circular to circular outer shapefunctioning as a stop against the keyhole 156 for additional distalmovement.

Referring to FIG. 2B, the distal end 32 of the clip-advancing wire 30also includes notches 250 along one side 251 of the distal end 32 whichhave a distal surface 252 substantially perpendicular to the side 251and proximal beveled surface 254. The coil connector 152 includes aresilient catch 256 in alignment with the notches 250. When theclip-advancing wire 30 is moved distally through the keyhole 156, thebeveled surface 254 of the notches 250 rides against the catch 256,bending the catch for clearance. However, as distal surface 252interferes with the catch 256 when the clip-advancing wire 30 is movedproximally relative to the coil connector 152, the clip-advancing wire30 may not be moved proximally by a distance which would cause a notch250 to pass the catch 256 (FIG. 2C).

Moreover, rotation of the clip-advancing wire 30 causes a rotationalmoment to be applied to the connector 152 and consequently the distalend of the tubular coil 12. The distal end of the preloaded tubular coil12 can be thereby rotated 360° in each of the clockwise andcounterclockwise directions by rotation of the rotation knob 62 attachedto the proximal end of the clip-advancing wire 30. Because the endeffector assembly 13 is attached to the distal end of the tubular coil,rotation of knob 62 effects rotation of the end effector assembly 13 andthe jaws 18, 20.

The end effector wires 22, 24 are large enough in diameter to preferablyhandle up to fifteen pounds of closing force from the handle assemblyand also to handle the force required to open the jaws 18, 20 withoutbuckling. However, the end effector wires must be small enough indiameter to attach to the jaws, and fit in the tubular coil 12. Apreferred diameter for the end effector wires is approximately 0.178 mmto 0.375 mm (0.007 inch to 0.015 inch), though other sizes may be used.

Referring to FIGS. 9 and 10, the clevis 14 of the end effector assembly13 is preferably coupled directly to the distal end of the tubular coil12. The clevis 14 includes a central clip channel 164 having apreferably rectangular cross section, and two lateral openings 165through which the distal ends of the end effector wires 26, 28 canrespectively exit. The jaws 18, 20 are each rotatably coupled about theclevis 14 with a respective axle 166 (one shown) which does notinterfere with the channel 164. Each jaw 18, 20 includes a proximal tang168, 169 respectively, which is coupled to the distal ends of therespective end effector wires 26, 28. The distal portion of each jaw 18,20 includes a clip guide 170, 172, respectively, and clamping surfaces174, 176 on jaw 18, and clamping surfaces 178, 180 on jaw 20 extendingalong each side of the guide 172. All of the clamping surfaces 174, 176,178, 180 preferably have proximally directed teeth 182 which pullstarget tissue toward the clip channel 164 as the jaws are closed, andalso securely grips the tissue when a clip is advanced thereover. Thedistal end of jaw 18 includes an anvil 184 which is in alignment withthe clip guide 170 which curves (or is angled) toward jaw 20. Jaw 20includes two distal anvil guides 186, 188 between which the anvil 184 ispositioned when the jaws are moved to a closed position. Jaw 20 alsodefines a distal well 190 between the anvil guides 186, 188 which islower than the surface of clip guide 172.

Referring to FIG. 11, a clip chamber 200 for storing a plurality oflinearly arranged clips 202 (FIG. 2A), described further below, isformed between the coil connector 152 (FIGS. 2 and 2A) and the distalend 16 of the tubular coil 12. The clip chamber 200 extends into theclip channel 164 of the clevis 14. The clip pusher 34 is provided at theproximal end of the chamber and situated to push on a proximalmost clipsuch that all clips in front of the clip pusher 34 are advanced towardthe jaws 18, 20 when the clip-advancing lever 52 is actuated to causethe clip-advancing wire 30 to move distally relative to the tubular coil12.

The clip pusher 34, preferably made of stainless steel, is coupled tothe distal end 32 of the clip-advancing wire 30, e.g., by mechanicaljoining or welding. The clip pusher 34, as described in more detailbelow, is provided with a shape substantially similar to the distalportion of a clip 202 (FIG. 2A) adapted to be used in the clip applier.Such clips 202 are described in detail in previously incorporated U.S.Ser. No. 09/891,775. Generally, referring to FIG. 2A, the clips 202 areeach in a generally U-shaped configuration with first and second arms204, 206, and a bridge portion 208 therebetween. The first arm 204extends into a deformable retainer 214 preferably having atissue-piercing end 216 and preferably also a hook 218, and the secondarm 206 is provided with a tip 210 preferably having one or more catches212. The clip 202 is provided with structure that facilitates thestacking (or chaining) of a plurality of clips in the clip chamber 200.The structure includes: a notch 220 at a junction of the second arm 206and the bridge portion 208 which is adapted to receive the tip 210 ofthe second arm 206 of another clip; an elongate recess 222 along theexterior of the first arm 204 which is adapted to receive the retainer214 of the first arm of another clip; and an interior configuration 224at the ends of the first and second arms which corresponds to anexterior shape of the proximal bridge portion 208 of another clip. Inone embodiment, the clips 202 are each approximately 6.86 mm (0.27 inch)in length from the bridge 208 to the end of the retainer 214, have awidth of approximately 0.90 mm (0.035 inch), and a height of 1.80 mm(0.070 inch). However, it is understood that the clip dimensions may beadapted for use in devices having tubular coil inner diameters ofvarious sizes.

Referring to FIGS. 2 and 2A, the clip pusher 34 includes a rear clipseat 228 which corresponds to the exterior shape of the proximal end ofthe clip. The clip pusher 34 also includes a distally extending arm 230having a distal clip catch 232 (adapted to seat in the recess 222 ofclip 202), and a shoulder 234 adjacent the clip seat 228 on the sideopposite the arm 230. As such, the clip pusher 34 includes structurewhich is adapted to conform the proximal end of a clip 202 fortransferring a pushing force relative to the tubular coil. In addition,the clip catch 232, by engaging in the recess 222 of a clip 202,prevents clips from unintentionally moving distally. The clip catch alsopermits moving a clip 202 proximally, by retracting the clip pusher 34such that the clip catch 232 forces back against wall at the rear of therecess 222 and pulls the engaged clip proximally, which in turn movesother clips in the ‘chain’. The operation of the distal portion of thedevice 10 (including the end effector assembly 13, the clip pusher 34,and the clip chamber 200) will become evident with reference to thefollowing description of the use of the device 10.

Referring to FIGS. 4 and 12, the jaw closing lever 48 is moved towardthe stationary handle 46, against the bias of spring 56, to cause thejaws 18, 20 of the end effector 13 to move into a closed position.Movement of the lever 48 adapts, in size, the distal end of the devicefor delivery through the lumen (working channel) of an endoscope, butpreferably does not substantially load the end effector wires 22, 24.Once the end effector assembly 13 has exited the distal end of theendoscope, the jaw closing lever 48 can be released to open the jaws(FIG. 1). Referring now to FIG. 13, the proximal rotation knob 62 can berotated which, as discussed above, effects rotation of the entireclip-advancing wire 30 and, hence, rotation of the end effector assembly13. Briefly, this is because the end effector assembly 13 is coupled tothe tubular coil 12 and the tubular coil is provided with a fixed coilconnector 152 which is rotated by rotation of the distal end 32 of theclip-advancing wire 30.

Turning now to FIG. 14, once the jaws 18, 20 of the end effectorassembly 13 are positioned on either side of tissue (not shown) aboutwhich it is desired to place a clip 202 (FIGS. 2 and 2A), the jawclosing lever 48 is again moved toward the stationary handle 46 to clampthe jaws about the tissue. The lever 48 is moved relatively further thanshown in FIG. 12, as the wires 22, 24 will be under load to compress thetissue. Referring back to FIGS. 9 and 10, the teeth 182 on the clampingsurfaces 174, 176, 178, 180 of the jaws 18, 20 are angled proximally topull the tissue into the jaws assembly and securely hold the tissueagainst the distally directed force of an advanced clip. As the jawsclose, the anvil 184 moves between the anvil guides 186, 188, and maypartially or fully pierce the tissue.

Once the jaws are fully clamped about the tissue, the locking tooth 90engages with the lever lock 110 as the latch 94 moves down to allowengagement and thereby lock the jaw closing lever 48 relative to thestationary handle 46, as discussed above with respect to FIGS. 6 and 7.As discussed above, the jaws are locked based upon the load in thehandle, rather than at any particular position. This permits locking thejaws about tissues of various thicknesses and compressive properties.Moreover, it is noted that when the jaws 18, 20 are fully clamped, theend effector wires 22, 24 are placed under tension which providescompression to the tubular coil 12 such that the coil has an effectivelyhigher tensile limitation before stretching.

Referring now to FIGS. 15 and 16, after the jaws are clamped about thetissue, the clip-advancing lever 52 is rotated about the pivot pin 54 toeffect advancement of the clip-advancing wire 30 through the tubularcoil 12. More particularly, as lever 52 is rotated toward the jawclosing lever 48, the pinion 70 engages the rack 68 to move the rackrelatively distally. As the proximal end of the clip-advancing wire 30is longitudinally fixed relative to the rack 68, the distal end 32 ofthe clip-advancing wire 30 is consequently moved distally. Referring toFIGS. 10 and 17, the pusher 34, at the distal end 32 of theclip-advancing wire 30 distally advances the clips 202 a, 202 b, 202 c,202 d in the chamber 200, and particularly forces the distalmost clip202 a through the channel 164 in the clevis 14 and between the jaws 18,20. As clip 202 a is further advanced, the first and second arms 204,206 ride in guides 170, 172, respectively, and are forced over thetissue held between the jaws 18, 20. When the retainer 214 on the firstarm 204 of the clip 202 a is forced against the anvil 184, the retainer214 is bent toward jaw 20; the tip 216 pierces the tissue between thejaws 18, 20 (or is guided into the pierce hole made by the anvil 184when the jaws clamped the tissue); and the tip 216 enters the well 190at the distal end of jaw 20 to extends around the tip 210 of the secondarm 206 which overhangs the well. The hook 218 at the tip 216 of theretainer 214 may engage (although it does not necessarily engage), thelatch 212 at the distal end of the second arm 206. The force provided bythe clip-advancing wire 30 to advance a clip 202 over the clampedtissue, to bend the retainer 214 against the anvil 184, and to force thetip 216 of the retainer to pierce tissue is at least 500 grams (1.1lbs), and more typically approaches 1500 grams (3.3 lbs) or higher.

Referring now to FIGS. 6 and 18, after the clip is applied, the jaws 18,20 are released from about the tissue. This is done by pressing therelease button 124 of the lever lock 110 such that the jaw closing lever48 is permitted to move relative to the stationary handle 46.

Referring to FIG. 19, the clip is then released from the end effectorjaw assembly by moving the jaw assembly relative to the applied clip 202a. The end effector assembly may then be moved to another tissuelocation to apply additional clips.

It is noted that after clip 202 a is released, the retainer 214 b ofclip 202 b partially extends into the space between the jaws 18, 20. Ifnot retracted, this retainer 214 b would obstruct positioning the jaws18, 20 about the tissue and subsequent clip application during theprocedure. However, when the clip-advancing lever 52 is released,torsion spring 58 (FIG. 4) operates to pull back the clip-advancing wire30 and the clip pusher 34 and thereby retract the ‘chain’ of clips. Thatis, the clip catch 232 of the clip pusher pulls back on clip 202 d, andthe retainer 214 d of clip 202 d pulls back clip 202 c, and so on, untilthe extending retainer 214 b is pulled within the chamber 164 of theclevis, and the space between the jaws 18, 20 is cleared, as shown inFIGS. 20 and 21. The clip-advancing wire is limited in the distance bywhich it can be retracted; it may be retracted only so far as permittedby interference of a ridge 250 on the clip-advancing wire 30 locatedjust distal the catch 256 of the coil connector 152, and the catch 256(FIG. 2B), which is constructed to be approximately the length of theprotruding retainer 214 b.

The device may then be used to apply another clip, or the jaws may beclosed and the device may be withdrawn through the endoscope.

The resulting clip applier is capable of transmitting a pushing force atthe distal end of the clip-advancing wire, resulting from thecompressive force appliable to the clip-advancing wire and the relativetensile force appliable to the outer tubular coil and end effectorwires, far in excess of the perceived threshold of the 200 grams (0.44lbs) in the prior art. In fact, as discussed below, one embodiment ofthe device of the invention provides a pushing force in excess of 2267grams (5 lbs).

More particularly, referring to FIG. 22, a table listing part dimensionsof six prototype device, and the resultant output forces achieved withprototype devices is provided. FIG. 23 provides an efficiency plot(input pushing force v. output pushing force) for the use of theprototypes. In all prototypes, the tubular coil, clip-advancing wire,and end effector wires are made from stainless steel. Details of thetable and the efficiency plot are discussed below with respect toExamples 1 through 6.

EXAMPLE 1

In a first prototype, indicated by ‘RUN #1’, ‘RUN #2’ and ‘RUN #3’, thetubular coil 12 has an outer diameter of 0.09 inch and an inner diameterof 0.06 inch. The clip-advancing wire 30 has an outer diameter of 0.017inch and the end effector wires 22, 24 each have an outer diameter of0.011 inch. The proximal end of the end effector wires 22, 24 are pulledwith 11 lbs of force which generally results in 5 to 10 lbs of force atthe distal end of the end effector wires, depending on the degree towhich the tubular coil 12 is bent (modeled by looping the tubular coilthrough two inch loops); i.e., frictional losses reduce the transmittedforce. Moreover, it is noted that whatever force is transmitted to thedistal end of the end effector wires 22, 24, only approximatelyone-fifth of that force is applied to the jaws, as the distance from thejaw tang 168 to the pivot 166 is relatively shorter than the length ofthe end of the jaw (anvil 184) to the pivot 166, approximately in a oneto five ratio. As such, an input force of 11 lbs may results in one totwo lbs of force on the jaws 18, 20. Applying the pulling forcesimulates the in-use condition in which the pushing force istransmitted.

With the tubular coil 12 extending relatively straight (i.e., through noloops) in ‘RUN #1’, an input pushing force of 8 lbs on the proximal endof the clip-advancing wire 30 (i.e., a pushing force of 8 lbs on therack 68) resulted in an output pushing force of 3.82 lbs (1732.7 grams)at the clip pusher 34 at the distal end 32 of the clip-advancing wire30. With the tubular coil 12 extending through one two-inch loop in ‘RUN#2’, an input pushing force of 8 lbs resulted in an output pushing forceof 3.42 lbs (1551.3 grams). With the tubular coil 12 extending throughtwo two-inch loops, in ‘RUN #3’, an input pushing force of 7 lbsresulted in an output pushing force of 3.37 lbs (1528.6 grams).

EXAMPLE 2

In a second prototype, indicated by ‘RUN #4’, the diameters of thetubular coil 12 and end effector wires 22, 24 are the same as Example 1.However, the diameter of the clip-advancing wire 30 is decreased to0.015 inch. With the tubular coil 12 extending through no loops, a sixpound input pushing force resulted in an output pushing force of 2.11lbs (957 grams).

EXAMPLE 3

In a third prototype, indicated by ‘RUN #5’, ‘RUN #6’ and ‘RUN #7’, thediameters of the tubular coil 12 and end effector wires 22, 24 are thesame as Example 1. However, the diameter of the clip-advancing wire 30is increased to 0.02 inch. With the tubular coil 12 extending through noloops in ‘RUN #5’, an input pushing force of 8 lbs resulted in an outputpushing force of 4.03 lbs (1828 grams). With the tubular coil 12extending through one two-inch loop in ‘RUN #6’, an input pushing forceof 8 lbs resulted in an output pushing force of 4.08 lbs (1851 grams).With the tubular coil extending through two two-inch loops, in ‘RUN #7’,an input pushing force of 8 lbs resulted in an output pushing force of3.54 lbs (1605.7 grams).

EXAMPLE 4

In a fourth prototype, indicated by ‘RUN #8’ and ‘RUN #9’, the deviceincludes a tubular coil 12 having an outer diameter of 0.086 inch and aninner diameter of 0.053 inch, a clip-advancing wire 30 having a diameterof 0.017 inch, and end effector wires 22, 24 having diameters of 0.009inch. With the tubular coil extending through no loops, an input pushingforce of 8 lbs resulted in 4.61 lbs (2091 grams) of output pushingforce. With the tubular coil extending through two two-inch loops, aninput pushing force of 8 lbs resulted in 4.28 lbs (1941.3 grams) ofoutput pushing force.

EXAMPLE 5

In a fifth prototype, indicated by ‘RUN #10’, the clip-advancing wire 30and end effector wires 22, 24 of the device 10 have the same diametersas Example 4. The tubular coil 12 has an outer diameter of 0.086 inchand an inner diameter of 0.054 inch. With the tubular coil 12 extendingthrough no loops, an input pushing force of 8 lbs resulted in 4.42 lbs(2004.9 grams) of output pushing force.

EXAMPLE 6

In a sixth prototype, indicated by ‘RUN #11’, the clip-advancing wire 30and end effector wires 22, 24 of the device 10 have the same diametersas Example 4. The tubular coil 12 has an outer diameter of 0.083 inchand an inner diameter of 0.054 inch. With the tubular coil 12 extendingthrough no loops, an input pushing force of 8 lbs resulted in 5.17 lbs(2345 grams) of output pushing force.

Other flexible clip appliers suitable for use through a relativelysmaller 2.6 mm diameter endoscope have also been constructed and tested.For example, one clip applier has a tubular coil 12 with an outerdiameter of 0.092 inch, and an inner diameter of 0.060 inch, aclip-advancing wire 30 with a diameter of 0.022 inch, and end effectorwires 22, 24 each with a diameter of 0.013 inch. The device can apply apushing force of between 3 lbs (1361 grams) and 5 lbs (2268 grams)depending on the number of two-inch loops through which the tubular coilwas wound.

It is therefore appreciated that other dimensions may be used fordevices intended for use in endoscopes having working channels of othersizes. Moreover, the device may be used outside an endoscope, where itis not limited by the size of the working channel.

From the foregoing examples, it will be appreciated that a flexiblesurgical clip applier, suitable for use through an endoscope is herebyprovided. The device is capable of effecting a pushing force far inexcess of the previously considered limitation of approximately 200grams for a mechanical system sized to be used through an endoscope. SeeC. Paul Swain, “What Endoscopic Accessories Do We Really Need?”,Emerging Technologies in Gastrointestinal Endoscopy, Gastrointest.Endosc., Vol. 7, No. 2, pp. 313-330 (April 1997), discussed above. Thissubstantial force permits clips to be forced over tissue and therebymakes available clip clamping, closure, and ‘suturing’ in an endoscopicprocedure.

There have been described and illustrated herein embodiments of aflexible surgical clip applier. While particular embodiments of theinvention have been described, it is not intended that the invention belimited thereto, as it is intended that the invention be as broad inscope as the art will allow and that the specification be read likewise.Thus, while particular materials have been disclosed, it will beappreciated that other materials can be used as well. In addition, whileparticular dimensions have been disclosed, it will be understood thatother suitable dimensions can be used as well. Also, while the devicehas particularly been described for use in endoscopic procedures, wherea great need exists for such a device, it will be appreciated thatflexible, non-endoscopic devices are considered within the scope of theinvention. For example, the tubular coil may have a substantiallyshorter length and the device may be used through body orifices such asthe ear canal, the nasal passages, and through the larynx and trachea.By way of another example, elements of the device may have substantiallylarger dimensions and the device can be used through a trocar port.Furthermore, while both jaws are shown rotatable about a clevis, it willbe appreciated that only one jaw need be rotatable relative to theother. Also, while two clip guides, one on each jaw, are shown, it isrecognized that only a single clip guide on one of the jaws is required.Moreover, while the device of the invention is described as having twoend effector wires, it will be appreciated that a single control wiremay be used which is coupled to at least one of the jaws, and the otherjaw may be stationary or mechanically linked to also close and open uponactuation of the single end effector wire. Also, while the device hasbeen described with respect to a clip-advancing wire and end effectorwires, it will be appreciated that reference to the ‘wires’ is intendedto also include non-metal filaments, multifilamentary constructs, suchas cables, and coils. In addition, while the end effector wires whensubject to a tensile force create a compressive force on the tubularcoil which effectively increases its tensile capability to facilitatepushing a clip over clamped tissue without exceeding the tensilelimitation of the coil, it is recognized that other mechanisms may beused to increase the tensile limitation of the coil. For example, apreferably flat and preferably wire ribbon may be coupled to the insidethe coil to limit the amount by which the coil can be stretched.Furthermore, while the ability to provide a relative high pushing forceat the distal end of a clip-advancing wire is disclosed with respect toa clip applier, it is recognized that such capability has application toinstruments other than clip appliers; for example, for endoscopicstaplers, lithotriptors, or any other instrument where it is desired tohold tissue and apply a pushing force, such as a device for tagging. Itwill therefore be appreciated by those skilled in the art that yet othermodifications could be made to the provided invention without deviatingfrom its spirit and scope as claimed.

1. A method for applying a clip to tissue, comprising: a) inserting intoa human body an instrument sufficiently flexible to be bent through a180° path, the instrument loaded with a single file linear arrangementof surgical clips; b) advancing a first clip over a first section oflayers of the tissue in a direction parallel to the layers; c) deformingthe first clip so that a portion of the first clip pierces the firstsection of the tissue; d) without removing the instrument from the humanbody, advancing a second clip over a second section of layers of thetissue in a direction parallel to the layers; and e) deforming thesecond clip so that a portion of the second clip pierces the secondsection of the tissue.
 2. A method according to claim 1, furthercomprising: f) clamping the first section of the tissue before advancingthe first clip; and g) clamping the second section of the tissue beforeadvancing the second clip.
 3. A method according to claim 1, wherein:each of the first and second clips includes first and second arms and abridge portion therebetween to together define a generally U-shapedconstruct, the first arm extending into a deformable retainer, whereinsaid deforming the first clip includes bending the retainer of the firstclip, and said deforming the second clip includes bending the retainerof the second clip.
 4. A method according to claim 3, wherein: saidbending the retainer of the first clip includes bending the retainer ofthe first clip about the second arm of the first clip, and said bendingthe retainer of the second clip includes bending the retainer of thesecond clip about the second arm of the second clip.
 5. A methodaccording to claim 4, wherein: the retainer of the first clip includes ahook, and the second arm of the first clip includes a catch for thehook, wherein when the retainer is bent about the second arm, the hookengages the catch.
 6. A method according to claim 1, wherein: saidinserting a flexible instrument into a human body includes inserting theinstrument through an endoscope.
 7. A method according to claim 1,wherein: said advancing a first clip includes pushing the first clipwith a force in excess of 500 grams.
 8. A method according to claim 1,wherein: said advancing a first clip includes pushing the first clipwith a force in excess of 1000 grams.
 9. A method according to claim 1,wherein: said advancing a first clip includes pushing the first clipwith a force in excess of 1500 grams.
 10. A method according to claim 1,wherein: said advancing a first clip includes pushing the first clipwith a force in excess of 2000 grams.
 11. A method according to claim 1,wherein: said inserting an instrument into the human body includesinserting an instrument sufficiently flexible to be bent through a 360°path.
 12. A method of applying a surgical clip to tissue, comprising: a)providing a surgical instrument including, i) a flexible outer tubularmember having proximal and distal ends, ii) a flexible clip-advancingelement extending through said tubular member and having proximal anddistal ends, iii) a jaw mount coupled to said distal end of said tubularmember, iv) a pair of jaws mounted on said jaw mount, at least one ofsaid pair of jaws being rotatable on said jaw mount relative to theother of said pair of jaws, each of said pair of jaws having a tissueclamping surface, and at least one of said pair of jaws having a clipguide, v) at least one control element having proximal and distal endsand extending through said tubular member, said distal end of each saidat least one control element being coupled to at least one of said pairof jaws, vi) a handle assembly coupled to said proximal ends of saidtubular member, said clip-advancing element, and said at least onecontrol element and adapted (A) to move said clip-advancing elementrelative to said tubular member, and (B) to move said at least onecontrol element relative to said tubular member to effect clamping ofsaid jaws about the tissue and release therefrom, vii) a clip chamberformed by at least one of said tubular member and said jaw mount adaptedto store at least one surgical clip, viii) a plurality of surgical clipsin said clip chamber, ix) a clip pusher at said distal end of saidclip-advancing element and adapted to advance the clips in said clipchamber; b) inserting said instrument into the human body; c) locatingsaid jaws about a first target tissue; d) operating said handle to causesaid tissue clamping surfaces of said jaws to clamp about said firsttarget tissue; and e) operating said handle to cause said clip pusher tobe forced distally relative to said distal end of said tubular memberwith sufficient force to advance a clip from said clip chamber throughsaid at least one clip guide and over said clamped first target tissue.13. A method according to claim 12, wherein: one of said jaws includesan anvil, and said operating said handle to advance said clip causes aportion of said clip to deform against said anvil.
 14. A methodaccording to claim 13, wherein: said deformation of said portion of saidclip causes said portion to bend or angle toward the other of said jaws.15. A method according to claim 14, wherein: said clip includes firstand second arms and a bridge portion therebetween to together define agenerally U-shaped construct, the first arm extending into a deformableretainer, wherein said deforming the clip includes bending the retainerof the clip.
 16. A method according to claim 15, wherein: said bendingthe retainer of the clip includes bending the retainer about the secondarm.
 17. A method according to claim 16, wherein: the retainer includesa hook, and the second arm includes a catch for the hook, wherein whenthe retainer is bent about the second arm, the hook engages the catch.18. A method according to claim 12, wherein: said inserting a flexibleinstrument into a human body includes inserting the instrument throughan endoscope.
 19. A method according to claim 12, wherein: saidoperating said handle to advance a clip includes pushing the first clipwith a force in excess of 500 grams.
 20. A method according to claim 12,wherein: said operating said handle to advance a clip includes pushingthe first clip with a force in excess of 1000 grams.
 21. A methodaccording to claim 12, wherein: said operating said handle to advance aclip includes pushing the first clip with a force in excess of 1500grams.
 22. A method according to claim 12, wherein: said operating saidhandle to advance a clip includes pushing the first clip with a force inexcess of 2000 grams.
 23. A method of providing an endoscopic pushingforce, comprising: a) providing a flexible instrument sized to beextended through the lumen of an endoscope and having a flexible outertubular member and a flexible inner member extending within and movablerelative to said outer tubular member, each of said outer tubular memberand said inner member having a distal end; and b) moving said innermember distally relative to said outer tubular member such that arelatively distal force of at least 500 grams is provided at said distalend of said inner member.
 24. A method according to claim 23, wherein:said distal force is at least 1000 grams.
 25. A method according toclaim 23, wherein: said distal force is at least 1500 grams.
 26. Amethod according to claim 23, wherein: said distal force is at least2000 grams.
 27. A method according to claim 23, further comprising: c)providing a compressive force to said tubular member when moving saidinner member distally relative to said outer tubular member.
 28. Amethod of operating a flexible surgical instrument having an flexibleouter tubular member with a tensile limitation, and a flexible innermember extending within said outer tubular member, comprising: a)providing a compressive force to the outer tubular member to increase atensile limitation of the outer tubular member; and b) providing a forcewhich is compressive to said inner member and tensile to said outertubular member while maintaining said compressive force on said outertubular member such that a pushing force in excess of 500 grams isprovided at said distal end of said inner member relative to said outertubular member.
 29. A method of effecting surgery, comprising: a)providing a flexible endoscopic instrument having i) a flexible coilouter tubular member, ii) a flexible inner member extending within saidouter tubular member, each of said outer tubular member and said innermember having respective proximal and distal ends, and iii) a proximalhandle coupled to said proximal ends of said outer tubular member andsaid inner member, said handle adapted to move said inner memberrelative to said outer tubular member; and b) operating said handle tocreate a tensile force of at least 500 grams at said distal end of saidouter tubular member.
 30. A method of applying a surgical clip totissue, comprising: a) providing a surgical instrument including, i) aflexible outer tubular member having proximal and distal ends, ii) aflexible clip-advancing element extending through said tubular memberand having proximal and distal ends, iii) a jaw mount coupled to saiddistal end of said tubular member, iv) a pair of jaws mounted on saidjaw mount, at least one of said pair of jaws being rotatable on said jawmount relative to the other of said pair of jaws, each of said pair ofjaws having a tissue clamping surface, and at least one of said pair ofjaws having a clip guide, v) at least one control element havingproximal and distal ends and extending through said tubular member, saiddistal end of each said at least one control element being coupled to atleast one of said pair of jaws, vi) a handle assembly coupled to saidproximal ends of said tubular member, said clip-advancing element, andsaid at least one control element and adapted (A) to move saidclip-advancing element relative to said tubular member, and (B) to movesaid at least one control element relative to said tubular member toeffect clamping of said jaws about the tissue and release therefrom,vii) a clip chamber, viii) a plurality of surgical clips in said clipchamber, ix) a clip pusher at said distal end of said clip-advancingelement and adapted to advance the clips in said clip chamber, wherein adistal end of said instrument is sized to be inserted through a lumen ofan endoscope; b) inserting said instrument through a lumen of anendoscope and into the human body; c) locating said jaws about a firsttarget tissue; d) operating said handle to cause said tissue clampingsurfaces of said jaws to clamp about said first target tissue; and e)operating said handle to cause said clip pusher to be forced distallyrelative to said distal end of said tubular member with sufficient forceto advance a clip from said clip chamber through said at least one clipguide and over said clamped first target tissue.
 31. A method forapplying a clip to tissue, comprising: a) inserting a flexibleinstrument into a human body, the instrument loaded with a plurality ofsurgical clips; b) advancing a first clip over a first section of thetissue, said first clip including first and second arms and a bridgeportion therebetween to together define a generally U-shaped construct,the first arm extending to become a plastically deformable retainer; c)plastically deforming the retainer of the first clip so that theretainer pierces the first section of the tissue; d) without removingthe instrument from the human body, advancing a second clip over asecond section of the tissue, the second clip including first and secondarms and a bridge portion therebetween to together define a generallyU-shaped construct, the first arm extending to become a plasticallydeformable retainer; and e) plastically deforming the retainer of thesecond clip so that the retainer pierces the second section of thetissue.
 32. A method for applying a clip to tissue, comprising: a)inserting a flexible instrument into a human body, the instrument loadedwith a plurality of surgical clips; b) advancing a first clip over afirst section of the tissue; c) deforming the first clip so that aportion of the first clip pierces the first section of the tissue; d)without removing the instrument from the human body, advancing a secondclip over a second section of the tissue; and e) deforming the secondclip so that a portion of the second clip pierces the second section ofthe tissue, wherein each of the first and second clips includes firstand second arms and a bridge portion therebetween to together define agenerally U-shaped construct, the first arm extending into a deformableretainer, wherein said deforming the first clip includes bending theretainer of the first clip, and said deforming the second clip includesbending the retainer of the second clip.
 33. A method according to claim32, wherein: said bending the retainer of the first clip includesbending the retainer of the first clip about the second arm of the firstclip, and said bending the retainer of the second clip includes bendingthe retainer of the second clip about the second arm of the second clip.34. A method according to claim 33, wherein: the retainer of the firstclip includes a hook, and the second arm of the first clip includes acatch for the hook, wherein when the retainer is bent about the secondarm, the hook engages the catch.
 35. A method of applying a surgicalclip to tissue, comprising: a) providing a surgical instrumentincluding, i) a flexible outer tubular member having proximal and distalends, ii) a flexible clip-advancing element extending through saidtubular member and having proximal and distal ends, iii) a jaw mountcoupled to said distal end of said tubular member, iv) a pair of jawsmounted on said jaw mount, at least one of said pair of jaws beingrotatable on said jaw mount relative to the other of said pair of jaws,each of said pair of jaws having a tissue clamping surface, and at leastone of said pair of jaws having a clip guide and one of said jaws havingan anvil, v) at least one control element having proximal and distalends and extending through said tubular member, said distal end of eachsaid at least one control element being coupled to at least one of saidpair of jaws, vi) a handle assembly coupled to said proximal ends ofsaid tubular member, said clip-advancing element, and said at least onecontrol element and adapted (A) to move said clip-advancing elementrelative to said tubular member, and (B) to move said at least onecontrol element relative to said tubular member to effect clamping ofsaid jaws about the tissue and release therefrom, vii) a clip chamberformed by at least one of said tubular member and said jaw mount adaptedto store at least one surgical clip, viii) a plurality of surgical clipsin said clip chamber, said clips having first and second arms and abridge portion therebetween to together define a generally U-shapedconstruct, the first arm extending beyond said second arm into adeformable retainer, ix) a clip pusher at said distal end of saidclip-advancing element and adapted to advance the clips in said clipchamber; b) inserting said instrument into the human body; c) locatingsaid jaws about a first target tissue; d) operating said handle to causesaid tissue clamping surfaces of said jaws to clamp about said firsttarget tissue, and advance said clip to deform said retainer againstsaid anvil of one of said jaws to cause said retainer to bend or angletoward the other of said jaws; and e) operating said handle to causesaid clip pusher to be forced distally relative to said distal end ofsaid tubular member with sufficient force to advance a clip from saidclip chamber through said at least one clip guide and over said clampedfirst target tissue.
 36. A method according to claim 35, wherein: saidbending the retainer of the clip includes bending the retainer about thesecond arm.
 37. A method according to claim 36, wherein: the retainerincludes a hook, and the second arm includes a catch for the hook,wherein when the retainer is bent about the second arm, the hook engagesthe catch.